French employees of the German tire maker Continental burned tires at a demonstration in Paris on Wednesday. Photo: Jacques Brinon/Associated Press

Just ask Fred Goodwin, the former chief executive of the ailing Royal Bank of Scotland, whose house and car were vandalized early Wednesday. Or Luc Rousselet, the manager of a 3M factory in France, who was barricaded in an office for a second day by workers demanding better severance packages for 110 employees who are being laid off.

While such instances are scattered so far, the angry mood threatens to overshadow the Group of 20 summit meeting next week in London, where world leaders hope to find approaches to the financial crisis.

Several protests are planned in London’s financial district, and the police are warning financial institutions to bolster security, cancel unnecessary meetings and keep employees inside. Bankers are being advised to wear “casual clothing” so they do not attract attention.

“A recession has all sorts of knock-on effects,” said Christopher Husbands, a professor of sociology at the London School of Economics. “Crimes go up, relationships break down and there are instances of civil disturbance.”

A nationwide strike in France last week, which drew at least 1.2 million people, was peaceful. But the government remains worried about an outbreak of violence similar to that last month in Guadeloupe, a French overseas territory, and in Greece in December.

The sense of frustration among those who lost their jobs or savings or a large part of their pension funds is fueled by reports of executives continuing to reap large rewards, as demonstrated by the outrage in the United States over bonuses paid at the American International Group. Europeans have long pointed out that pay packages of top executives in the United States are simply out of whack with the rest of the world, but their hopes of avoiding a public outcry were doused by the latest reports of inflamed local passions.

In Scotland, vandals smashed at least three windows on the ground floor of Mr. Goodwin’s house in an affluent suburb of Edinburgh and damaged a black Mercedes S600 parked in the driveway. Mr. Goodwin was not in the house at the time and no one was hurt, but the incident alarmed Britain’s business community.

A spokesman for Prime Minister Gordon Brown, who is in the United States, said “there could be no excuse for people breaking the law.”

Mr. Goodwin attracted criticism for keeping his pension, worth £703,000 a year, or $1.03 million, despite a string of ill-timed acquisitions on his watch that led to the bank’s being brought under government control. He rejected calls to surrender the payment, and the government is considering legal options.

It was the first such attack on a property owned by a banking executive since the financial crisis started, but some neighbors told local newspapers they were surprised it did not happen earlier.